The quality of a particular ride or other transportation activity provided by service providers of a transportation network influences the degree of affinity that the users of the network feel for the network. In extreme cases of poor transportation quality, certain users may feel prompted to cease using the network's transportation services, either indefinitely or for a prolonged period of time. It would be desirable in such cases for the transportation network to be able to contact the users in order to address the problem. Unfortunately, it is difficult to formulate a set of ad hoc rules that accurately capture the variety and subtle interactions of different factors that influence the users' perceptions of the quality of the transportation, and it is even more difficult to determine when a particular user will be in danger of ceasing to use the transportation network's services.